Oxytalan Elastic and Collagen Fibers During the Repair Process in Experimental Nitric Oxide Inhibition

Abstract

XAVIER-VIDAL R Oxytalan elastic and collagen fibers during the repair process in experimental nitric oxide inhibition.CLINICS 60(2):85-92, 2005. PURPOSE:To evaluate the repair process in rats with experimentally induced arterial hypertension. This study aimed to evaluate lesions in the ventricular myocardium and the repair process during experimental hypertension induced by systemic blockage of nitric oxide using N-omega-nitro-L-arginine methyl ester hydrochloride (L-NAME). Nitric oxide is an endothelial vasorelaxing factor and is necessary for the maintenance of normal arterial pressure, and L-NAME is an analog and antagonist of L-arginine, the substrate of the nitric oxide synthase. MATERIALS AND METHODS:We used 26 normotensive young male Wistar rats belonging to several litters. Animals were treated with oral administration of L-NAME dissolved in water (75 mg/100 mL) for 43 days . Hearts were weighed and processed by routine methods. Special stains utilized were Gomori's trichrome (aniline blue), picrosirius red polarization to identify fibrillar collagen, alcian blue technique (pH 0.5 and pH 2.5) to identify glycosaminoglycans, periodic acid-Schiff technique (with and without amylases) to identify proteoglycans, and Weigert's resorcinol fuchsin solution (with and without oxone) to identify elastic fibers. RESULTS:The results showed significant elevation of the arterial pressure (P <0.01) and significant increase of cardiac weight (P <.0001) in the L-NAME (hypertensive) treated group, as compared to an untreated control group. The histological analysis demonstrated wide infarcted myocardial areas in animals with nitric oxide blockade; several vascular changes such as thickening of the muscular tunica with fibrosis; thickening in the wall of small arteries and arterioles; and fibrinoid necrosis in the wall to nearly complete luminal obliteration. Reparative fibrosis involved mainly oxytalan elastic and collagen fibers.CONCLUSION: Oxytalan elastic and collagen fibers are of great importance for the postinfarct repair process occurring during experimental nitric oxide inhibition. KEYWORDS: Oxytalan elastic fibers. Collagen fibers. Nitric oxide. Arterial hypertension. Repair.Hypertension is a common disorder in modern industrial countries. 1 In men, arterial hypertension is the most important risk factor in cardiovascular disease, affecting 11% to 20% of the Brazilian population over 20 years of age. In Brazil, cardiovascular diseases are the number-one cause of mortality, representing about 30.8% of the total deaths. 2 About 90% to 95% of arterial hypertension is idiopathic, CLINICS 60(2): [85][86][87][88][89][90][91][92] 2005 Oxytalan elastic and collagen fibers during the repair process Xavier-Vidal R et al.CLINICS 60 (2): [85][86][87][88][89][90][91][92] 2005 Oxytalan elastic and collagen fibers during the repair process Xavier-Vidal R et al.CLINICS 60 (2): [85][86][87][88][89][90][91][92] 2005 Oxytalan elastic and collagen fibers during the repair process Xavier-Vidal R et al.

Diabetes Alters Intracellular Calcium Transients in Cardiac Endothelial Cells

“…Eight-week-old female Sprague Dawley rats (SAS SD Strain 400, Charles River) were injected intraperitoneally with 70 mg/kg streptozotocin (STZ, Sigma-Aldrich) and allowed to develop type I diabetes for six weeks [41] , with diabetic phenotype confirmed by serum glucose levels greater than 300 mg/dl. To assess DCM-associated cardiac fibrosis, fibrillar collagen content was measured using picrosirius red staining of paraffin sections of myocardium [42] . The stained sections were observed under polarized light and photographed with the same exposure time for each section.…”

Dyes and Stains: from molecular structure to histological application

“…Weigert's resorcin-Fuchsin staining is also extensively applied in the present, for example to investigate the remodelling process in idiopathic interstitial pneumonia, which shows a progressive vascular fibroelastosis in lung (91)(92). In addition to clinical studies, Weigert's stain has also been utilized in basic research to evaluate the ventricular myocardium lesion and the repairing process after experimental induced hypertension, showing the increase of elastic fibers as a key event in postinfarct repair (93). Unlike the techniques recently described, Orcein is a progressive stain for elastic fibers and for this reason does not require a differentiation step, being simpler and easier to perform (5).…”